Reasons Why Head Gaskets Fail

Your vehicle head gasket sits between your motor car's cylinder head and engine block. It's been designed to perform several critical jobs. But it's prime job is to prevent coolant leaks as well as sealing off the combustion chambers.

If a head gasket fails, the resulting damage to your car engine can be considerable. The problem here is... that a failure doesn't always prevent you from driving your vehicle. In some cases it gradually worsens until you're forced to either completely overhaul your engine or totally replace it. Here are some of the reasons head gaskets fail.

Reason #1. Overheating

An engine that is overheating is one of the leading causes of a blown head gasket. When an engine overheats, it undergoes a thermal expansion along with the cylinder head. And because the head gasket lies between them both the thermal expansion can crush it. Once the gasket gets crushed, the special seal that it maintains will will out fail break down. This is bad because it causes leaks in both the coolant level and compression. When engine coolant leaks from the block and gains entry into the crankshaft, it can destroy the bearings. If compression leaks, you will notice a reduction in your car's performance and gas mileage. Plus you'll usually experience occasional misfires. This won't prevent you from driving, but a blown head gasket will ultimately need to be addressed.

Reason #2. Poor Installation

The ability of the head gasket to maintain a proper seal between the engine block and cylinder head is absolutely crucial in order for it to prevent leaks. It's really important to realize if the part is installed incorrectly, then the seal will be ineffective.

How can this possibly happen?

Actually it happens more than it should. Sometimes a mechanic might use the wrong head bolts, and/or put them on incorrectly. Or even worse, use torque wrenches that might be improperly calibrated. Yet another installation problem might be that the surface of the engine block may not have been machined properly. That can prevent the head gasket from creating a thorough seal, which will lead to coolant and compression leaks.

Reason #3. Design Issues

Manufactuer design faults are another cause of failure. Many modern cars have cylinder heads constructed from aluminum in order to reduce their weight. But the engine blocks are still made of cast iron. The problem here is that aluminum expands at a different rate and usually more quickly than cast iron. In high-temperature conditions, the variance in expansion rates can create rubbing between the block and cylinder head.

That rubbing creates immense stress on the head gasket and can eventually damage it altogether. There are several more reasons why head gaskets often fail, such as a detonation problem within the engine caused by a lean fuel mixture. Problems within a car's cooling system, including both the radiator, water pump, and even the head gasket itself can be a contributing factor. That said, overheating, poor installation, and undue stress from thermal expansion (especially with aluminum cylinder heads) tends to cause most head gasket failures. In conclusion, it's crucial that you have a mechanic address a head gasket problem as soon as it rears its ugly head! Follow this simply advice and you will avoid expensive damage to your engine. You can find helpful advice on replacing your car fuses.